The present invention relates to a microphone mounting structure, and in particular, a microphone mounting structure which permits easy and reliable conversion of a conventional respirator to a sound amplifying respirator.
It is known that conventional respirators make communications difficult between persons wearing the respirators. In particular, the wearer's voice is muffled and difficult to detect over significant distances. This problem is exacerbated when there is background noise, as during firefighting and other similarly hazardous emergency operations. In response to this problem, several attempts have been made to provide sound amplifying respirators and/or masks which facilitate communications among the wearers of the respirators and masks. Examples of such respirators and masks are illustrated by the following U.S. Patents:
______________________________________ U.S. Pat. No. PATENTEE ______________________________________ 5,307,793 Sinclair et al. 5,224,473 Bloomfield 5,159,641 Sopko et al. 5,138,666 Bauer et al. 5,060,308 Bieback 4,537,276 Confer 4,508,936 Ingalls 4,491,699 Walker 4,116,237 Birch 4,072,831 Joscelyn 3,314,424 Berman 3,180,333 Lewis 2,953,129 Bloom et al. 2,950,360 Duncan ______________________________________
Although the above exemplary respirators and masks are generally effective, there are several disadvantages associated therewith. The Joscelyn patent, for example, teaches a mounting structure for the microphone which is integrally formed with the mask. Thus, retro-fitting of existing masks with the arrangement of Joscelyn would be very difficult and time-consuming.
Still other disadvantages are associated with one or several ones of the above exemplary respirators and masks. These disadvantages include significant reductions in amplification quality resulting in distortion of the amplified voice; the need for expensive and excessively complex circuitry or manufacturing techniques; serious distortion if the mask is frequently bumped or otherwise subject to frequent quick movements; incompatibility with some irregularly shaped masks and smaller masks, such as filter masks; mounting of the microphone assembly to the mask using a threaded connection which may become loosened during extended use, such loosening of the threaded connection possibly compromising the air-tightness of the mask and thereby posing an extreme danger to the user of the masks in hazardous environments; and difficulty in removing the microphone temporarily from the mask for purposes of cleaning the mask.